Eh, I guess I'm going forget about the one that never responded. I have it pretty well with the new one anyway.

If this is your choice, I'd tell girl B that you went out with girl A but there wasn't really any chemistry. In fact, mention something that girl A did that you found "weird". This way, when girl A inevitably tries to cock block you from girl B, girl B will have a "reason" to question girl A's input (after all, you weren't into girl A and she therefore will be negative about you).